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The paper deals with the possibilities of reducing the consumption of electrical energy of the impact screwdriver during the assembly of fixed threaded joints. The recommendations related to a decrease in electrical energy consumption would allow reducing product costs but so far there have been no such recommendations from the producers of the tool as to the effective operating regimes of the impact screwdrivers in relation to electrical energy consumption and necessary tightening moment of the nut.The aim of the study is to find out the economical operating mode of the electrical impact screwdriver when assembling fixed threaded joints. By varying the set speed of the rotor head and working time of the impact mechanism, there is an opportunity to determine electrical energy consumption of the tool for the given tightening moment.The results of the experiment show that at the same tightening moment obtained the electrical energy consumption of the impact screwdriver is less at a higher starting set speed of the rotor head but shorter operating time of the impact mechanism than at a lower speed of the rotor head and longer operating time of the impact mechanism.

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Estimates are obtained of the rate of convergence in limit theorems in the max-scheme of independent identically distributed random variables (i.i.d.r.v.'s) under linear and power normalizations, when the maximum is taken over a subsequence of natural numbers {k(n)} satisfying the condition limn_.,~ k(n + l)/k(n) = r, 1 < r < oo.

In this paper, a kinematic analysis of Theo Jansen’s stepping mechanism has been carried out and an algorithm for finding the output link trajectory from the given dimensions of the stepping mechanism elements, implemented by Mathcad program, has been developed. It is possible to output characterising parameters of all intermediate links with any number of intermediate links of a step cycle of the mechanism. The dimensions of the mechanism elements have been selected so that they provide the optimal smooth trajectory of the stepping point, minimising the mechanism oscillations in the vertical plane. A comparison of the trajectories of the foot in this study with the classical trajectory of Theo Jansen and the trajectory from article [7] has been provided. A minimum swing of the oscillation of the centre of mechanism masses in the vertical plane has been selected as an optimality criterion, combined with the maximum smoothness of the trajectory, provided that maximization of the step height is not required.